Distance-meter.



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T. CHABREQ DISTANCE METER.

APPLICATION min-JAN. 10. ms.

' 2 SHEETS-SHEET I.

IN VENTOR 1 ZVZeodore fi j Patented Feb. 6, 1917.

T- CHABRE.

DISTANCE METER.

APPLICATION FILED 11111.10, l9l6 Patented Feb. 6, 1917.

2 SHEETS-SHEET 2 IN VENTOR WGOOZOTEZ ['ZQZM? \VITNESSES:

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THEODORE CHABRE, OF AIIAMEDA, CALIFORNIA.

DISTANCE-METER.

' with a pair of telescopes rigidly mounted at right angles to each other and adapted to turn on a plane which will permit observation and taking of horizontal angles, the 1nstrument being provided with the usual alidade, Vernier, etc., for this purpose. Another object of the invention is to provide a centrally disposed shutter for closing ofl one telescope while the other is being used, Further objects will hereinafter appear.

The invention consists of the parts and the construction and combination of parts as hereinafter more fully described and claimed, having reference to the accompanying drawings, in which- Figure 1 is a perspective view of the 1nstrument.

Fig. 2 is a central, same. 7

Fig. 3 is a diagrammatic view, showing one use of the instrument.

Referring to the drawings in detail, A indicates a suitably shaped base member which is adapted to be secured on top of a tripod 2 by means of the threaded extension 3 and the nut 4. The upper end of the base member is divided into two sections 5 and 6, one of which is removable. Formed interiorly of said sections is a socket which is provided for the purpose of receiving a ball 7 formed on the lower end of a spindle 8. For the purpose of locking the ball, with connected spindle 8, in any adjusted position desired a ring 9 has been provided. This surrounds the upper edge of sections 5 and6 and is provided with a pair of clamping screws 10 which engage with the sections 5 and 6 to force the same inwardly to exert the desired clamping action or pressure desired.

Turnably mounted exteriorly of the spindle is a sleeve member 11. On the upper end of which is formed a head 12 provided for the purpose of supporting a pair of telescopes 13 and 14. These telescopes are rigidly connected and mounted on the head 12 at right angles to each other. They are severtical section of Specification of Letters Patent.

Patented Feb. 6,1917.

Application filed January 10 1916. Serial No. 71,235.

cured in position on top of the head 12 by means of a cap 15 secured by screws 16. The telescopes are provided with any suitable form of objective lenses 17 and eyepieces 19; the only difference between a standard telescope and the present one being that the eye-pieces carrying the tube sections are turnable about the main telescope tube and provided with levels 20 to permit the cross hairs in the eye-pieces to be turned to a horizontal position when necessary. The instrument is otherwise provided with the usual. alidade 21 carrying verniers 22 registering with a graduated limb 23 for the purpose of permitting observation or taking of horizontal angles. The center of the alidade corresponds to the intersection of the telescopes.

Mountedin the cap 15 and centrally positioned between the intersecting telescope tubes 13 and 14 is a cylindrical shaped shutter 24, provided with a handle 25 on its upper end to permit it to be turned from one position to another.

Formed in the lower cylindrical end of the shutter is a pair of oppositely disposed openlngs 26 of a diameter corresponding to the interior diameter of the telescope tubes.

These openings are adapted to be brought into alinement with one tube or the other by turning the shutter by the handle 25. This is of considerable importance as it is possible to close one telescope while observing through the other. It also provides a means for intercepting any light which might enter through the opposite telescope;

The instrument as a whole is provided for the purpose of measuring distances by means of taking right angularly disposed angles. This is possible as two rig t angularly disposed telescopesare provided.

In actual practice or operation, by referring to Fig. 3 one use of the instrument can be seen. It is always necessary to use two instruments when surveying or taking any observation, one being placed at the point B and. another at the point C. For the purpose of distinguishing one instrument from the other B will be known. as the station instrument and C as the observing instrument. The station instrument is first set up with one of the telescopes in alinement with the base line B D and the other telescope in alinement with the center} of the observing instrument orpointing in the direction of line B G. The observing instrument is then turned into the position shown with one oi? its telescopes pointing directly to the point D which is the object whose distance from the station point B is to be measured. It is then possible to read on the protrac't-or the angularyalue of the angle BCE; the distance BE being short compared with the distance BD may then be measured and as this is in direct proportion to the distance BD it is possible to determine said distance Without further measurement.

-Havin-g thus described my invention, What I claim and desire to secure by Letters Patent is 1. In a surveying instrument, the combination With a base member having a spindle mounted thereon,-of a sleeve tur-nable on the spindle, a head member carried by the sleeve, and a pair of telescopes rigidly secured on the head and positioned at right angles to each other.

2. In a surveying instrument, the combination With a base member having a spindle mountedthereon, of a sleeve turnable on the spindle, a head member carried by the sleeve, and a pair of telescopes rigidly secured on the head and intersecting and pos'i-tioned at right angles to each other.

3. In a surveying instrument, the combi nation With a base member having a spindle mounted thereon, of a sleeve turnable on the spindle, a head member carriedby the sleeve, a pair of telescopes rigidly secured on the head and intersecting and positioned at right angles 'to each other, and a turnably mounted shutter positioned at the intersect- Copies of this patent may be obtained for ing point of the telescopes adapted to close one telescope or the other.

at. In a surveying instrument, the combination with a base member and a spindle on said base member, of a sleeve turnable on said spindle, a head carried by said sleeve, a

pair of telescopes secured on the head and scopes adapted to close one telescope or the.

other.

6. A survey instrument comprising a pair of telescopes mounted at right angles to each other and adapted to turn in a horizontal plane, and means associated with said telescopes for measuring horizontal angles, the intersection of said telescopes correspending to the-center of said angle measuring means.

In testimony whereof I have hereunto set my hand in the presence of two subscribing Witnesses. V

THEODORE CHABR-E. Witnesses:

JOHN H. HERm-Ne, TV. W. HEALEY.

five cents each, by addressing the Commissioner of Iatents,

Washington, 20.0.7 

